How to use the Radioddity HF-010 antenna on your car roof

--By Ed Durrant DD5LP

When operating the Radioddity HF-010 “Static mobile” or “Portable-Parked” (do not have this antenna roof-mounted when the car is in motion), the setup process differs from that described in the handbook for use of this antenna with its supplied tripod / ground-stake / radials configuration.

Due to the size of this antenna, it is recommended to use a 3-magnet roof mount, not a single-magnet one. Radioddity sells the M916 three-foot magnetic base. The additional PL259 adapter HF-010A, from Radioddity, is required to stabilise the tall antenna on the mount and also to convert from PL259 to the 3/8 x 24 threaded mount used by the antenna.

As the car roof will now be acting as the ground plane for the vertical, coil-loaded antenna, depending upon how much metal is contained in the roof, settings will vary between cars, and you will need to calibrate your antenna/mount/car-roof to band, setting configuration yourself using some kind of antenna analyser.

In this configuration, the HF-010’s feed-point piece is not used (its role being taken by the car roof magnetic antenna base). The radials, coax reel, tripod and stake are also not required. While the two extender rods can be used to lift the antenna higher, doing so makes the adjustment of the slider on the loading coil very difficult.

Hence, the parts required are:
i.   3-Foot Magnetic car roof antenna mount e.g. Radioddity M916 (with SO239 socket and coax to go back to your radio).
ii.  Base adapter HF-010A.
iii. Slider coil section (marked 5-18MHz).
iv. The telescopic whip.
v.  Antenna analyser (until you have your list of settings) 

My tests (on a 2022 Citroen C3 roof) were all without extender sections and with the telescopic whip fully extended.

As regards bands above 17m, the telescopic whip will need to be reduced in length, and you will need to find a way to mark how many sections should be extended, or perhaps measure the length with the tape measure which is supplied with the HF-010.

For 80m, the additional 80m coil needs to be added, but whether using this with or without the slider section, the bandwidth covered within the 80/75m band is not practical, as it is very small in the order of 25-50 kHz.

Performance:The HF-010, car roof-mounted, works well on 17 – 60 metres, but I would not use it for 80 metres, and while you can use it on 15, 12 & 10m, the HF-010 brings no advantage over other telescopic whip solutions from other manufacturers on these bands. Having this massive antenna on the car roof certainly draws interest from passers-by!

Have Fun! 73 Ed Durrant DD5LP.